Cisco CCNA 200-301 Quality of Service (QoS) Practice Test

Topic 29 focuses on Quality of Service (QoS) for the Cisco Certified Network Associate (CCNA) certification and the 200-301 exam, using Cisco networking and Cisco IOS concepts where relevant. For broader exam preparation, review the Cisco CCNA 200-301 Exam Dumps page. Each question includes a concise explanation of the correct answer and the technical reason the other choices are incorrect.

Question 1

What is the QoS process of identifying traffic so different classes can receive different treatment?

1. Policing
2. Marking
3. Congestion management
4. Classification

Correct Answer: D

 

Correct Answer

Answer D is correct because the selected answer describes the QoS process of identifying traffic so different classes can receive different treatment.

Incorrect Answers

Answer A is incorrect because the “Policing” option describes a different concept: a QoS mechanism that enforces a rate and typically drops or remarks traffic that exceeds the configured limit.

Answer B is incorrect because the “Marking” option describes a different concept: the QoS process of setting fields such as DSCP or CoS to indicate a traffic class.

Answer C is incorrect because the “Congestion management” option describes a different concept: QoS techniques that control how packets are scheduled when an interface cannot immediately transmit all offered traffic.

 

Question 2

What is the QoS process of setting fields such as DSCP or CoS to indicate a traffic class?

1. Marking
2. Best effort
3. Policing
4. Queuing

Correct Answer: A

 

Correct Answer

Answer A is correct because the selected answer describes the QoS process of setting fields such as DSCP or CoS to indicate a traffic class.

Incorrect Answers

Answer B is incorrect because the “Best effort” option describes a different concept: Default packet treatment in which traffic receives no special delivery guarantee or priority.

Answer C is incorrect because the “Policing” option describes a different concept: a QoS mechanism that enforces a rate and typically drops or remarks traffic that exceeds the configured limit.

Answer D is incorrect because the “Queuing” option describes a different concept: the process of holding packets awaiting transmission and scheduling which queued traffic is sent first.

 

Question 3

What is an IEEE 802.1p Layer 2 priority value carried in the 802.1Q tag?

1. Shaping
2. CoS
3. Queuing
4. DSCP

Correct Answer: B

 

Correct Answer

Answer B is correct because the selected answer describes an IEEE 802.1p Layer 2 priority value carried in the 802.1Q tag.

Incorrect Answers

Answer A is incorrect because the “Shaping” option describes a different concept: a QoS mechanism that buffers excess traffic and delays transmission to smooth traffic toward a configured rate.

Answer C is incorrect because the “Queuing” option describes a different concept: the process of holding packets awaiting transmission and scheduling which queued traffic is sent first.

Answer D is incorrect because the “DSCP” option describes a different concept: a Layer 3 marking in the IP header used to signal per-hop behavior.

 

Question 4

What is a Layer 3 marking in the IP header used to signal per-hop behavior?

1. CoS
2. DSCP
3. Best effort
4. Queuing

Correct Answer: B

 

Correct Answer

Answer B is correct because the selected answer describes a Layer 3 marking in the IP header used to signal per-hop behavior.

Incorrect Answers

Answer A is incorrect because the “CoS” option describes a different concept: an IEEE 802.1p Layer 2 priority value carried in the 802.1Q tag.

Answer C is incorrect because the “Best effort” option describes a different concept: Default packet treatment in which traffic receives no special delivery guarantee or priority.

Answer D is incorrect because the “Queuing” option describes a different concept: the process of holding packets awaiting transmission and scheduling which queued traffic is sent first.

 

Question 5

What is the process of holding packets awaiting transmission and scheduling which queued traffic is sent first?

1. Queuing
2. Classification
3. Best effort
4. Marking

Correct Answer: A

 

Correct Answer

Answer A is correct because the selected answer describes the process of holding packets awaiting transmission and scheduling which queued traffic is sent first.

Incorrect Answers

Answer B is incorrect because the “Classification” option describes a different concept: the QoS process of identifying traffic so different classes can receive different treatment.

Answer C is incorrect because the “Best effort” option describes a different concept: Default packet treatment in which traffic receives no special delivery guarantee or priority.

Answer D is incorrect because the “Marking” option describes a different concept: the QoS process of setting fields such as DSCP or CoS to indicate a traffic class.

 

Question 6

Which term describes qoS techniques that control how packets are scheduled when an interface cannot immediately transmit all offered traffic?

1. Trust boundary
2. Best effort
3. Queuing
4. Congestion management

Correct Answer: D

 

Correct Answer

Answer D is correct because QoS techniques that control how packets are scheduled when an interface cannot immediately transmit all offered traffic.

Incorrect Answers

Answer A is incorrect because the “Trust boundary” option describes a different concept: the point in the network where existing QoS markings begin to be accepted rather than overwritten.

Answer B is incorrect because the “Best effort” option describes a different concept: Default packet treatment in which traffic receives no special delivery guarantee or priority.

Answer C is incorrect because the “Queuing” option describes a different concept: the process of holding packets awaiting transmission and scheduling which queued traffic is sent first.

 

Question 7

Which QoS mechanism enforces a rate and typically drops or remarks traffic that exceeds the configured limit?

1. Policing
2. Congestion management
3. Classification
4. CoS

Correct Answer: A

 

Correct Answer

Answer A is correct because the selected answer describes a QoS mechanism that enforces a rate and typically drops or remarks traffic that exceeds the configured limit.

Incorrect Answers

Answer B is incorrect because the “Congestion management” option describes a different concept: QoS techniques that control how packets are scheduled when an interface cannot immediately transmit all offered traffic.

Answer C is incorrect because the “Classification” option describes a different concept: the QoS process of identifying traffic so different classes can receive different treatment.

Answer D is incorrect because the “CoS” option describes a different concept: an IEEE 802.1p Layer 2 priority value carried in the 802.1Q tag.

 

Question 8

Which QoS mechanism buffers excess traffic and delays transmission to smooth traffic toward a configured rate?

1. Shaping
2. Marking
3. Queuing
4. Policing

Correct Answer: A

 

Correct Answer

Answer A is correct because the selected answer describes a QoS mechanism that buffers excess traffic and delays transmission to smooth traffic toward a configured rate.

Incorrect Answers

Answer B is incorrect because the “Marking” option describes a different concept: the QoS process of setting fields such as DSCP or CoS to indicate a traffic class.

Answer C is incorrect because the “Queuing” option describes a different concept: the process of holding packets awaiting transmission and scheduling which queued traffic is sent first.

Answer D is incorrect because the “Policing” option describes a different concept: a QoS mechanism that enforces a rate and typically drops or remarks traffic that exceeds the configured limit.

 

Question 9

What is the point in the network where existing QoS markings begin to be accepted rather than overwritten?

1. Trust boundary
2. DSCP
3. Queuing
4. Congestion management

Correct Answer: A

 

Correct Answer

Answer A is correct because the selected answer describes the point in the network where existing QoS markings begin to be accepted rather than overwritten.

Incorrect Answers

Answer B is incorrect because the “DSCP” option describes a different concept: a Layer 3 marking in the IP header used to signal per-hop behavior.

Answer C is incorrect because the “Queuing” option describes a different concept: the process of holding packets awaiting transmission and scheduling which queued traffic is sent first.

Answer D is incorrect because the “Congestion management” option describes a different concept: QoS techniques that control how packets are scheduled when an interface cannot immediately transmit all offered traffic.

 

Question 10

Which term describes default packet treatment in which traffic receives no special delivery guarantee or priority?

1. Marking
2. Congestion management
3. Best effort
4. Shaping

Correct Answer: C

 

Correct Answer

Answer C is correct because it describes default packet treatment in which traffic receives no special delivery guarantee or priority.

Incorrect Answers

Answer A is incorrect because the “Marking” option describes a different concept: the QoS process of setting fields such as DSCP or CoS to indicate a traffic class.

Answer B is incorrect because the “Congestion management” option describes a different concept: QoS techniques that control how packets are scheduled when an interface cannot immediately transmit all offered traffic.

Answer D is incorrect because the “Shaping” option describes a different concept: a QoS mechanism that buffers excess traffic and delays transmission to smooth traffic toward a configured rate.

 

Question 11

For Classification, which statement is accurate?

1. QoS techniques that control how packets are scheduled when an interface cannot immediately transmit all offered traffic.
2. A QoS mechanism that buffers excess traffic and delays transmission to smooth traffic toward a configured rate.
3. The QoS process of identifying traffic so different classes can receive different treatment.
4. A QoS mechanism that enforces a rate and typically drops or remarks traffic that exceeds the configured limit.

Correct Answer: C

 

Correct Answer

Answer C is correct because it accurately defines Classification. The matching definition is: The QoS process of identifying traffic so different classes can receive different treatment.

Incorrect Answers

Answer A is incorrect because the “Congestion management” option describes a different concept: QoS techniques that control how packets are scheduled when an interface cannot immediately transmit all offered traffic.

Answer B is incorrect because the “Shaping” option describes a different concept: a QoS mechanism that buffers excess traffic and delays transmission to smooth traffic toward a configured rate.

Answer D is incorrect because the “Policing” option describes a different concept: a QoS mechanism that enforces a rate and typically drops or remarks traffic that exceeds the configured limit.

 

Question 12

For Marking, which statement is accurate?

1. The point in the network where existing QoS markings begin to be accepted rather than overwritten.
2. The QoS process of setting fields such as DSCP or CoS to indicate a traffic class.
3. A QoS mechanism that buffers excess traffic and delays transmission to smooth traffic toward a configured rate.
4. A QoS mechanism that enforces a rate and typically drops or remarks traffic that exceeds the configured limit.

Correct Answer: B

 

Correct Answer

Answer B is correct because the choice accurately describes Marking: The QoS process of setting fields such as DSCP or CoS to indicate a traffic class.

Incorrect Answers

Answer A is incorrect because the “Trust boundary” option describes a different concept: the point in the network where existing QoS markings begin to be accepted rather than overwritten.

Answer C is incorrect because the “Shaping” option describes a different concept: a QoS mechanism that buffers excess traffic and delays transmission to smooth traffic toward a configured rate.

Answer D is incorrect because the “Policing” option describes a different concept: a QoS mechanism that enforces a rate and typically drops or remarks traffic that exceeds the configured limit.

 

Question 13

For CoS, which statement is accurate?

1. The point in the network where existing QoS markings begin to be accepted rather than overwritten.
2. The process of holding packets awaiting transmission and scheduling which queued traffic is sent first.
3. A QoS mechanism that buffers excess traffic and delays transmission to smooth traffic toward a configured rate.
4. An IEEE 802.1p Layer 2 priority value carried in the 802.1Q tag.

Correct Answer: D

 

Correct Answer

Answer D is correct because the selected answer describes an IEEE 802.1p Layer 2 priority value carried in the 802.1Q tag.

Incorrect Answers

Answer A is incorrect because the “Trust boundary” option describes a different concept: the point in the network where existing QoS markings begin to be accepted rather than overwritten.

Answer B is incorrect because the “Queuing” option describes a different concept: the process of holding packets awaiting transmission and scheduling which queued traffic is sent first.

Answer C is incorrect because the “Shaping” option describes a different concept: a QoS mechanism that buffers excess traffic and delays transmission to smooth traffic toward a configured rate.

 

Question 14

For DSCP, which statement is accurate?

1. A Layer 3 marking in the IP header used to signal per-hop behavior.
2. An IEEE 802.1p Layer 2 priority value carried in the 802.1Q tag.
3. A QoS mechanism that enforces a rate and typically drops or remarks traffic that exceeds the configured limit.
4. A QoS mechanism that buffers excess traffic and delays transmission to smooth traffic toward a configured rate.

Correct Answer: A

 

Correct Answer

Answer A is correct because the selected answer describes a Layer 3 marking in the IP header used to signal per-hop behavior.

Incorrect Answers

Answer B is incorrect because the “CoS” option describes a different concept: an IEEE 802.1p Layer 2 priority value carried in the 802.1Q tag.

Answer C is incorrect because the “Policing” option describes a different concept: a QoS mechanism that enforces a rate and typically drops or remarks traffic that exceeds the configured limit.

Answer D is incorrect because the “Shaping” option describes a different concept: a QoS mechanism that buffers excess traffic and delays transmission to smooth traffic toward a configured rate.

 

Question 15

For Queuing, which statement is accurate?

1. The QoS process of setting fields such as DSCP or CoS to indicate a traffic class.
2. A QoS mechanism that buffers excess traffic and delays transmission to smooth traffic toward a configured rate.
3. The process of holding packets awaiting transmission and scheduling which queued traffic is sent first.
4. QoS techniques that control how packets are scheduled when an interface cannot immediately transmit all offered traffic.

Correct Answer: C

 

Correct Answer

Answer C is correct because it accurately defines Queuing. The matching definition is: The process of holding packets awaiting transmission and scheduling which queued traffic is sent first.

Incorrect Answers

Answer A is incorrect because the “Marking” option describes a different concept: the QoS process of setting fields such as DSCP or CoS to indicate a traffic class.

Answer B is incorrect because the “Shaping” option describes a different concept: a QoS mechanism that buffers excess traffic and delays transmission to smooth traffic toward a configured rate.

Answer D is incorrect because the “Congestion management” option describes a different concept: QoS techniques that control how packets are scheduled when an interface cannot immediately transmit all offered traffic.

 

Question 16

For Congestion management, which statement is accurate?

1. A QoS mechanism that enforces a rate and typically drops or remarks traffic that exceeds the configured limit.
2. The process of holding packets awaiting transmission and scheduling which queued traffic is sent first.
3. The QoS process of setting fields such as DSCP or CoS to indicate a traffic class.
4. QoS techniques that control how packets are scheduled when an interface cannot immediately transmit all offered traffic.

Correct Answer: D

 

Correct Answer

Answer D is correct because the choice accurately describes Congestion management: QoS techniques that control how packets are scheduled when an interface cannot immediately transmit all offered traffic.

Incorrect Answers

Answer A is incorrect because the “Policing” option describes a different concept: a QoS mechanism that enforces a rate and typically drops or remarks traffic that exceeds the configured limit.

Answer B is incorrect because the “Queuing” option describes a different concept: the process of holding packets awaiting transmission and scheduling which queued traffic is sent first.

Answer C is incorrect because the “Marking” option describes a different concept: the QoS process of setting fields such as DSCP or CoS to indicate a traffic class.

 

Question 17

For Policing, which statement is accurate?

1. The point in the network where existing QoS markings begin to be accepted rather than overwritten.
2. QoS techniques that control how packets are scheduled when an interface cannot immediately transmit all offered traffic.
3. A QoS mechanism that enforces a rate and typically drops or remarks traffic that exceeds the configured limit.
4. The QoS process of identifying traffic so different classes can receive different treatment.

Correct Answer: C

 

Correct Answer

Answer C is correct because the selected answer describes a QoS mechanism that enforces a rate and typically drops or remarks traffic that exceeds the configured limit.

Incorrect Answers

Answer A is incorrect because the “Trust boundary” option describes a different concept: the point in the network where existing QoS markings begin to be accepted rather than overwritten.

Answer B is incorrect because the “Congestion management” option describes a different concept: QoS techniques that control how packets are scheduled when an interface cannot immediately transmit all offered traffic.

Answer D is incorrect because the “Classification” option describes a different concept: the QoS process of identifying traffic so different classes can receive different treatment.

 

Question 18

For Shaping, which statement is accurate?

1. A QoS mechanism that enforces a rate and typically drops or remarks traffic that exceeds the configured limit.
2. A QoS mechanism that buffers excess traffic and delays transmission to smooth traffic toward a configured rate.
3. The QoS process of setting fields such as DSCP or CoS to indicate a traffic class.
4. The point in the network where existing QoS markings begin to be accepted rather than overwritten.

Correct Answer: B

 

Correct Answer

Answer B is correct because the selected answer describes a QoS mechanism that buffers excess traffic and delays transmission to smooth traffic toward a configured rate.

Incorrect Answers

Answer A is incorrect because the “Policing” option describes a different concept: a QoS mechanism that enforces a rate and typically drops or remarks traffic that exceeds the configured limit.

Answer C is incorrect because the “Marking” option describes a different concept: the QoS process of setting fields such as DSCP or CoS to indicate a traffic class.

Answer D is incorrect because the “Trust boundary” option describes a different concept: the point in the network where existing QoS markings begin to be accepted rather than overwritten.

 

Question 19

For Trust boundary, which statement is accurate?

1. Default packet treatment in which traffic receives no special delivery guarantee or priority.
2. QoS techniques that control how packets are scheduled when an interface cannot immediately transmit all offered traffic.
3. The point in the network where existing QoS markings begin to be accepted rather than overwritten.
4. The QoS process of identifying traffic so different classes can receive different treatment.

Correct Answer: C

 

Correct Answer

Answer C is correct because it accurately defines Trust boundary. The matching definition is: The point in the network where existing QoS markings begin to be accepted rather than overwritten.

Incorrect Answers

Answer A is incorrect because the “Best effort” option describes a different concept: Default packet treatment in which traffic receives no special delivery guarantee or priority.

Answer B is incorrect because the “Congestion management” option describes a different concept: QoS techniques that control how packets are scheduled when an interface cannot immediately transmit all offered traffic.

Answer D is incorrect because the “Classification” option describes a different concept: the QoS process of identifying traffic so different classes can receive different treatment.

 

Question 20

For Best effort, which statement is accurate?

802. An IEEE 802.1p Layer 2 priority value carried in the 802.1Q tag.
803. Default packet treatment in which traffic receives no special delivery guarantee or priority.
804. The process of holding packets awaiting transmission and scheduling which queued traffic is sent first.
805. The QoS process of setting fields such as DSCP or CoS to indicate a traffic class.

Correct Answer: B

 

Correct Answer

Answer B is correct because the choice accurately describes Best effort: Default packet treatment in which traffic receives no special delivery guarantee or priority.

Incorrect Answers

Answer A is incorrect because the “CoS” option describes a different concept: an IEEE 802.1p Layer 2 priority value carried in the 802.1Q tag.

Answer C is incorrect because the “Queuing” option describes a different concept: the process of holding packets awaiting transmission and scheduling which queued traffic is sent first.

Answer D is incorrect because the “Marking” option describes a different concept: the QoS process of setting fields such as DSCP or CoS to indicate a traffic class.

 

Question 21

During a service-verification task, the design calls for the following capability: The QoS process of identifying traffic so different classes can receive different treatment. Which option names that capability most accurately?

1. Queuing
2. Best effort
3. Classification
4. Trust boundary

Correct Answer: C

 

Correct Answer

Answer C is correct because Classification is the most precise fit for the stated requirement. The QoS process of identifying traffic so different classes can receive different treatment.

Incorrect Answers

Answer A is incorrect because the “Queuing” option describes a different concept: the process of holding packets awaiting transmission and scheduling which queued traffic is sent first.

Answer B is incorrect because the “Best effort” option describes a different concept: Default packet treatment in which traffic receives no special delivery guarantee or priority.

Answer D is incorrect because the “Trust boundary” option describes a different concept: the point in the network where existing QoS markings begin to be accepted rather than overwritten.

 

Question 22

A router writes a DSCP value into packets after assigning them to a traffic class. Which QoS action is it performing?

1. Queuing
2. Best effort
3. Marking
4. Classification

Correct Answer: C

 

Correct Answer

Answer C is correct because the scenario is describing the role of Marking. The QoS process of setting fields such as DSCP or CoS to indicate a traffic class.

Incorrect Answers

Answer A is incorrect because the “Queuing” option describes a different concept: the process of holding packets awaiting transmission and scheduling which queued traffic is sent first.

Answer B is incorrect because the “Best effort” option describes a different concept: Default packet treatment in which traffic receives no special delivery guarantee or priority.

Answer D is incorrect because the “Classification” option describes a different concept: the QoS process of identifying traffic so different classes can receive different treatment.

 

Question 23

While working on an operations troubleshooting session, an administrator encounters this requirement: An IEEE 802.1p Layer 2 priority value carried in the 802.1Q tag. Which answer is the most precise match?

1. Congestion management
2. DSCP
3. Queuing
4. CoS

Correct Answer: D

 

Correct Answer

Answer D is correct because CoS directly provides the function required by the scenario. An IEEE 802.1p Layer 2 priority value carried in the 802.1Q tag.

Incorrect Answers

Answer A is incorrect because the “Congestion management” option describes a different concept: QoS techniques that control how packets are scheduled when an interface cannot immediately transmit all offered traffic.

Answer B is incorrect because the “DSCP” option describes a different concept: a Layer 3 marking in the IP header used to signal per-hop behavior.

Answer C is incorrect because the “Queuing” option describes a different concept: the process of holding packets awaiting transmission and scheduling which queued traffic is sent first.

 

Question 24

In a branch-services review, the team must identify the technology that provides the following function: A Layer 3 marking in the IP header used to signal per-hop behavior. Which option should be selected?

1. DSCP
2. Classification
3. Best effort
4. Marking

Correct Answer: A

 

Correct Answer

Answer A is correct because the operational requirement in the stem maps to DSCP: A Layer 3 marking in the IP header used to signal per-hop behavior.

Incorrect Answers

Answer B is incorrect because the “Classification” option describes a different concept: the QoS process of identifying traffic so different classes can receive different treatment.

Answer C is incorrect because the “Best effort” option describes a different concept: Default packet treatment in which traffic receives no special delivery guarantee or priority.

Answer D is incorrect because the “Marking” option describes a different concept: the QoS process of setting fields such as DSCP or CoS to indicate a traffic class.

 

Question 25

An egress interface holds packets during congestion and selects which waiting traffic to transmit next. Which QoS function manages this process?

1. Queuing
2. Shaping
3. Best effort
4. Classification

Correct Answer: A

 

Correct Answer

Answer A is correct because Queuing is the most precise fit for the stated requirement. The process of holding packets awaiting transmission and scheduling which queued traffic is sent first.

Incorrect Answers

Answer B is incorrect because the “Shaping” option describes a different concept: a QoS mechanism that buffers excess traffic and delays transmission to smooth traffic toward a configured rate.

Answer C is incorrect because the “Best effort” option describes a different concept: Default packet treatment in which traffic receives no special delivery guarantee or priority.

Answer D is incorrect because the “Classification” option describes a different concept: the QoS process of identifying traffic so different classes can receive different treatment.

 

Question 26

During a service-verification task, the design calls for the following capability: QoS techniques that control how packets are scheduled when an interface cannot immediately transmit all offered traffic. Which option names that capability most accurately?

1. Queuing
2. Marking
3. Shaping
4. Congestion management

Correct Answer: D

 

Correct Answer

Answer D is correct because the scenario is describing the role of Congestion management. QoS techniques that control how packets are scheduled when an interface cannot immediately transmit all offered traffic.

Incorrect Answers

Answer A is incorrect because the “Queuing” option describes a different concept: the process of holding packets awaiting transmission and scheduling which queued traffic is sent first.

Answer B is incorrect because the “Marking” option describes a different concept: the QoS process of setting fields such as DSCP or CoS to indicate a traffic class.

Answer C is incorrect because the “Shaping” option describes a different concept: a QoS mechanism that buffers excess traffic and delays transmission to smooth traffic toward a configured rate.

 

Question 27

Traffic above a configured rate is dropped or remarked immediately rather than buffered to smooth its rate. Which QoS mechanism is being applied?

1. Best effort
2. Trust boundary
3. DSCP
4. Policing

Correct Answer: D

 

Correct Answer

Answer D is correct because Policing directly provides the function required by the scenario. A QoS mechanism that enforces a rate and typically drops or remarks traffic that exceeds the configured limit.

Incorrect Answers

Answer A is incorrect because the “Best effort” option describes a different concept: Default packet treatment in which traffic receives no special delivery guarantee or priority.

Answer B is incorrect because the “Trust boundary” option describes a different concept: the point in the network where existing QoS markings begin to be accepted rather than overwritten.

Answer C is incorrect because the “DSCP” option describes a different concept: a Layer 3 marking in the IP header used to signal per-hop behavior.

 

Question 28

While working on an operations troubleshooting session, an administrator encounters this requirement: A QoS mechanism that buffers excess traffic and delays transmission to smooth traffic toward a configured rate. Which answer is the most precise match?

1. Queuing
2. Shaping
3. DSCP
4. Best effort

Correct Answer: B

 

Correct Answer

Answer B is correct because the operational requirement in the stem maps to Shaping: A QoS mechanism that buffers excess traffic and delays transmission to smooth traffic toward a configured rate.

Incorrect Answers

Answer A is incorrect because the “Queuing” option describes a different concept: the process of holding packets awaiting transmission and scheduling which queued traffic is sent first.

Answer C is incorrect because the “DSCP” option describes a different concept: a Layer 3 marking in the IP header used to signal per-hop behavior.

Answer D is incorrect because the “Best effort” option describes a different concept: Default packet treatment in which traffic receives no special delivery guarantee or priority.

 

Question 29

In a branch-services review, the team must identify the technology that provides the following function: The point in the network where existing QoS markings begin to be accepted rather than overwritten. Which option should be selected?

1. Shaping
2. Trust boundary
3. Queuing
4. DSCP

Correct Answer: B

 

Correct Answer

Answer B is correct because Trust boundary is the most precise fit for the stated requirement. The point in the network where existing QoS markings begin to be accepted rather than overwritten.

Incorrect Answers

Answer A is incorrect because the “Shaping” option describes a different concept: a QoS mechanism that buffers excess traffic and delays transmission to smooth traffic toward a configured rate.

Answer C is incorrect because the “Queuing” option describes a different concept: the process of holding packets awaiting transmission and scheduling which queued traffic is sent first.

Answer D is incorrect because the “DSCP” option describes a different concept: a Layer 3 marking in the IP header used to signal per-hop behavior.

 

Question 30

A traffic class receives ordinary forwarding without reserved service, special priority or a delivery guarantee. Which treatment describes it?

1. Policing
2. Best effort
3. Marking
4. Shaping

Correct Answer: B

 

Correct Answer

Answer B is correct because the scenario is describing the role of Best effort. Default packet treatment in which traffic receives no special delivery guarantee or priority.

Incorrect Answers

Answer A is incorrect because the “Policing” option describes a different concept: a QoS mechanism that enforces a rate and typically drops or remarks traffic that exceeds the configured limit.

Answer C is incorrect because the “Marking” option describes a different concept: the QoS process of setting fields such as DSCP or CoS to indicate a traffic class.

Answer D is incorrect because the “Shaping” option describes a different concept: a QoS mechanism that buffers excess traffic and delays transmission to smooth traffic toward a configured rate.